Addition agent for lubricants



Patented Nov. 21, 1944 W. Gaynor, Chicago, Ill., assiznors to Standard I Oil Company, Chicago, 111., a corporation of Indian No Drawing. Application November 28, 1940,

Serial No. 367,594

13 Claims. (01. 252-46) The present invention relates to lubricating oils containing addition agents for use in automotive engines; and toe method for'modifying certain addition agents in order to improve their effect on the proper-ties of the lubricating oil.

. It is an object of the presentinvention to improve the properties of lubricants by modifying the addition agents therefor either before addi tion to the lubricant or in situ.

More particularly, the present invention relates to such addition agents as phosphatides and commercial mixtures 'of the same. The former include, for example, lecithin and cephalin, while the latter usually comprise a mixture of the two together with fatty oil and free fatty acids. The commercial mixtures frequently contain about 65% phosphatides, based on phosphorus content, and about 35% of fatty oil and fatty acid. Whenever the terms phosphatides or phosphatidic material appear herein it is to be understood that not only the pure compounds such as lecithin and cephalin, but also the commercial mixtures of lecithin, cephalin, oil, etc. are intended.

It is known that the addition of phosphatides to oils improves the quality thereof by preventing ring sticking and by acting as detergents and antioxidants. It has now been found that the effect of phosphatides, when used as addition agents, may be greatly improved by sulfurization, the resulting sulfurized phosphatides imparting extreme pressure properties to the lubricant. In addition to this advantage, sulfurized phospatides also improve the resistance of oils to oxidation. It is to be particularly noted, furthermore, that sulfurization of the phosphatides does not affect the detergent properties which characterize untreated phosphatides. The sulfurization of phosphatides may be carried out separately. and the product added to the lubricant or if desired the reaction may be carried out in the lubricating oil itself or in another inert diluent. The sulfurlzation of phosphatides may also be carried out in the presence of other oils for instance olefin polymers such as the trimer, tetramer, etc. of isobutyl ene or fatty oils such as snerm .oil. etc. Under these circumstances both the phosphatides and the oil are sulfurized at the same time and are, both added to the lubricating oil.

Sulfurized phosphatides may be added to the lubricating' oil alone or together with untreated nhosnha i s or wit addi ional sulfurized inhibitors such as sulfurized fatty oil, sulfurized olefin polymers or sulfurized mineral oil. When i it is desired to add the last-mentioned inhibitors to an oil the sulfurization thereof and the Sillfurization of the phosphatides is preferably carried out in one operation a stated above.

As stated hereinbefore, the sulfurization of the phosphatides does not minimize the detergent properties of the untreated phosphatide but rather improves the addition agent so that extreme pressure properties are imparted to the lubricating 011.

Three samples of an S. A. E. 20 lubricating o:-i1containing 1%, 2 /2 and 5%, respectively, of sulfurized phosphatides were subjected to the lAlmen test to determine the extreme pressure characteristics. The results of the tests were as follows:

Almen test Percent suliurized phosphatides Passed Failed Pounds is separated from the sulfurized phosphatides. As

. a specific example, four parts of commercial phosphatide were heated to about 280 F. and one part 7 of sulfur was then added. The mass was s irred for about one hour at temperatures of fro 280 F. to 290 F. After cooling, three volumes 0 hexane were added to the reaction mass and th' solution allowed to stand for several hours at 0 F. in orderto permit any remaining free sulfur to settle out. It is obvious that other inert extraction agents may be used instead ofhexane such as light petroleum naphthas, petroleum ether and the like. The clear solution was then filtered cold and the hexane evaporated under vacuum at a temperature less than F. The resulting product was dark red rubbery material which was soluble in a lubricating oil at about 200 F. It is to be particularly noted, however, that if temperatures in excess of 300 F. are used during the reaction between the phosphatides and the sulfur, and if the time of reaction exceed: three hours, the product is a tough, rubbery material which is substantially insoluble in an S. A, E. 20 lubricating oil even when the oil has been heated to more than 300 F. Care must, .therefore, be taken to limit the time of heating of the phosphatides and sulfur to not more than three hours and also to limit the temperature to not more than 300 F. If these limitations are observed thereaction product which is obtained can be dissolved readily in lubricating oil at temperatures of be.- tween 200 F. and 300 F. However, if reaction temperatures of the order. of 100 F. to 250 F.

'7. A process for preparing a sulrurized phosphatidic material comprising heating a "phosphatidic material in the presence of elemental I sulfur to a temperature below about 300 F. for a are used, a suitable product is obtained even when the time of heating exceeds three hours. In .par-

' ticular, when temperatures ofabout 100 F. are

used, the time of heating may be from to hours or even longer. The modified addition agent has a sulfur content of from about 2% to.

about 15% but usually the product contains from about 6% to about 7% sulfur. It is possible ito combine, chemically, sulfur with the phosphatidic material by'treating the material with a sulfurphosphorus compound, such as Past. Under these circumstances, some of the phosphorus may also be combined with the phosphatide. This product will have certain beneficial properties in addition to those obtained by merely sulfurizing the phosphatidic material. I

,Although the foregoing description has referred particularly to lubricating oils, however, other lubricants such as grease derive the same benefits from the sulfurized phosphatides and are therefore contemplated in the present invention. The foregoing description is not to be construed as a limitation of th invention since various modifications will be readily apparent to one skilled in r the art without departing from the spirit of the invention. The present invention is to be limited solely by the appended claims.

We claim:

1. A lubricating oil additive consisting of a sul-. furized phosphatidic material.

2. A lubricating oil additive consisting of a phosphatidic material containing chemically bound sulfur.

3. A lubricating oil additive as claimed in claim 1 wherein the sulfur content is from about 2% to about 15% 4. A lubricating oil additive as claimed in claim 1 wherein the pho'sphatidic material comprises a mixture of lecithin and cephalin.

5. A lubricating oil additive as claimed in claim 1 wherein the phosphatldicmateria? comprises lecithin. I v

6. A lubricating oil additive as claimed in claim 1 wherein the phosphatidic material comprises ce'phalin.

period of time insuflicient to form a tough, rubery. substantially oil insoluble material.

8. A- process for preparing a sulfurized phatidic material comprising mixing a "phosphatidic material" with elemental sulfur, heating the mixture to a temperature of from about 200 F. to about 300 F. while agitating, for a period of time insuflicient to form a tough, rubbery, substantially oil insoluble material, and separating excess free sulfur from the reaction product.

9. A process for preparing a sulfurized "phosphatidic material comprising heating a mixture of a phosphatidic material and elemental sulfur toa' temperature of from about 200 F. to about 300 F. for a period of from 1 to 2 hours while agitating, cooling the reaction mass, adding an extraction agent, fllteringto remove excess free sulfur and finally evaporating the filtrate under vacuum at a temperature below about 135 F. to remove the extraction agent.

10. A process for preparing a sulfurized iphosphatidic material comprising heating a "phosphatidic material to about 280 F., adding one part elemental sulfur to about four parts oi the heated "phosphatidic material, agitating the mass for about one hour while maintaining a temperature of from about 280 F. to about 290 F., cooling the reaction mass, adding about three volumes of hexane, settling out the free sulfur at about 0 F., filtering the solution while cold to remove excess free sulfur, and evaporating the filtrate under vacuum at a temperature below 12. A composition of matter comprising an ef iectiv'e amount to about five per cent sulfurized phosphatidic material" and a lubricating on, the amount of sulfurized phosphatidic material being sumcient to impart extreme pressure characteristics to the lubricating oil.

13. A composition of matter as claimed in claim 4 12 wherein the sulfurized phosphetidic inste-v rial contains from about two per cent to about fifteen per cent sulfur. V

CLARENCE M. LOANE. JAMES W. GAYNOR. 

